Identifying obstructive sleep apneoa and treating it with continuous positive airway pressure (CPAP) can significantly lower diastolic but not syystolic blood pressure in patients with treatment resistant say US researchers.
This US randomised trial – published in JAMA today – studied 194 patients with treatment-resistant hypertension (on three or more antihypertensives) and OSA. They were randomly assigned to receive CPAP or no CPAP and normal blood pressure control medications were maintained in each group throughout the duration of the study. The primary endpoint of the study was the change in 24-hour mean blood pressure after 12 weeks.
The CPAP group achieved a 3.1 mmHg greater decrease in 24-hour average blood pressure and 3.2 mmHg greater decrease in 24-hour diastolic BP but the difference in change in 24-hour systolic BP (a drop of 3.1mmHg) was not statistically significant compared to the control group.
More than 70% of US patients with treatment resistant hypertension have OSA
The researchers noted that there was a ‘among patients with obstructive sleep apnoea and resistant hypertension, continuous positive airway pressure treatment for 12 weeks compared with control resulted in a decrease in 24-hour mean and diastolic blood pressure and an improvement in the nocturnal blood pressure pattern’ but advise that ‘further research is warranted to assess longer-term health outcomes’.